Euclidis elementorum libri XV. Accessit XVI. de solidorum regularium comparatione. Omnes perspicuis demonstrationibus, accuratisque scholiis illustrati ..

Rome: Bartholomeo Grassi, 1589. SECOND CLAVIUS EDITION. Engraved titles, text within ruled borders, numerous diagrams and charts throughout. Contemporary vellum, author and title in contemporary ink on spines; some minor spotting, but over all an excellent set from the library of J. Ernest G. Yalden (1870-1937), creator and first superintendant of the Baron DeHirsch Trade School of New York City, with his bookplate on both paste-downs. Second edition edited by Clavius. “In 1574 a new departure in the matter of format was taken. A Latin edition in two octavo volumes with rather diminutive diagrams was printed at Rome by Vincenzo Accolti. The [editor] was Christophorus Clavius (Schlüssel) of Bamberg, of the Society of Jesus, a mathematician who gave the Gregorian Calendar of New Style its present form and made all the calculations necessary for its verification. It contains the fifteen books with very full scholia, and the addition of a sixteenth, De solidorum regularium comparatione [written by Clavius]. It was reprinted at Rome in 1589 in the same form, and in folio at Cologne in 1591" (Thomas-Stanford, p. 11). Clavius’ edition is not a simple translation but an overview of other commentators and editors, as well as his original notes and comments.

Clavius (1537-1612), a German Jesuit scholar, was a prominent astronomer and mathematician and teacher of mathematics in the Jesuit College of Rome. He was probably the most productive of all the German scholars of the sixteenth century to extend the knowledge of mathematics and was called, by his contemporaries, the Euclid of the sixteenth century. A friend and correspondent of Galileo, Clavius was known for his work on the reform of the calendar as well as his famous commentary of Euclid.

Adams, E 987; Thomas-Stanford, 22.